The present invention relates to a control unit for track-bound vehicles which are capable of exchanging data telegrams with a center via transmitting and receiving equipment.
U.S. Pat. No. 4,015,804, whose disclosure is incorporated herein by reference, which has a Claim for Priority based on German Published patent application DT-OS 2,423,590 discloses an hierarchically organized vehicle control system wherein a plurality of vehicles are controlled from command and control centers. This necessitates vehicle on-board control equipment which must perform a large number of different functions with fail-safety.
Such on-board control equipment has so far been developed specifically for continuous (long-haul) automatic train control, and as a rule, a special, fail-safe circuit has been provided for each function.
Such a solution has little flexibility and becomes very expensive if the number of functions to be performed by the control equipment increases. This is the case, for example, in short-distance traffic systems such as the one described in the above-cited U.S. Patent. In the demand-controlled system described there, an increase in the cost of the vehicle control unit has particularly unfavorable consequences since in the interest of efficient demand control, the use of many small vehicle units instead of few large ones considerably increases the share of the vehicle control units in the total cost of the system.